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Japan Space Communications Technology

Japan Successfully Launches Solid Fuel Rocket (oann.com) 107

randomErr writes: Japan successfully launched a solid fuel rocket named Epsilon-2. The 26-meter-long rocket launched from the Uchinoura Space Center at about 8 p.m. local time. Japan Aerospace Exploration Agency (JAXA) said this is the latest in Tokyo's effort to stay competitive in an industry that has robust growth potential and strong security implications. Also, this is to curb costs for rocket launches. The Epsilon-2 three-stage rocket [is part of a new generation of solid propellant rockets that aim] to put communication and weather satellites in space.
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Japan Successfully Launches Solid Fuel Rocket

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  • by ChoGGi ( 522069 ) <slashdot@choggi.org> on Wednesday December 21, 2016 @06:11AM (#53528559) Homepage

    https://www.nasaspaceflight.co... [nasaspaceflight.com]

    • Not to belittle their achievement, but it has to be said (with a tongue in the eye/twinkle in cheek): China achieved this already in the 7th century!

    • Thank you. That "article" is one of the worst things I have ever read, the only saving grace being that besides being completely contentless it was also short. And why are we driving eyeballs to this unknown newsrag anyhow?

      This article, from your link [nasaspaceflight.com] describes the first Epsilon launch in 2013 and generally the development projects which led up to it. Quoting the overview:

      Epsilon, which will replace the M-V rocket which was retired in 2006, is a three or four stage rocket which combines upper stages used on

      • There is a political aspect to it. Solid fuel rockets are ideal for ballistic missiles because they can be kept on standby with little to no maintenance. This is a dual-use technology that means Japan could produce intercontinental ballistic missiles if it wanted to. This is the exact thing North Korea was forbidden to do by the UN.

        Of course more whining from North Korea is not likely to be noticed, but it won't help relations with China either.

        • I have a hard time agreeing with that. I'm not a rocket scientist, but I think there are a number of things which detract from that argument. The principles of solid fuel rockets are pretty solidly nailed down, especially in terms of chemistry, and while solid fuel does have certain conveniences, ballistic missiles can run just fine on alcohol, jet fuel, kerosene, or whatever is lying around. Almost anyone could produce ballistic missiles, it's a lot easier [wikipedia.org] than putting something in orbit. JAXA building one

          • by tibit ( 1762298 )

            A ballistic missile doesn't have a problem with excessive velocity as long as it can survive the aerodynamic pressure and heating. Trajectories can be designed to mitigate the fixed burn time of the motor. So a solid-motor ballistic missile isn't a big deal. Even if you didn't have any way to throttle it down. Alas, solid motors can certainly be throttled down by blowing some of the exhaust sideways, and even turned off by blowing out the flames - as long as you design that capability in.

            • Yes, you can design solid rockets so that they can be throttled or turned off, but at that point you're lifting a lot of useless fuel, and given that this rocket was used to put something in orbit, that's going to be quite a lot of fuel. Using a non-optimal trajectory adds quite a bit of aerodynamic load and heat. With rockets you of course want to minimize the amount of non-payload mass you're moving, so if you're anticipating that you might not want to take the most efficient path through the atmosphere,

          • Oh dear... There really is not that vast a difference between a high energy sub-orbital flight and a full orbital flight. With a little modification ballistic missiles can and have been used to launch satellites, and visa versa orbit capable rockets make very good missile platforms. In the old cold war days the biggest nuclear warheads could only be delivered by planes or large space rockets - like the Soyuz for instance.. In its early days the Space Shuttle was described as the most capable nuclear warh

            • There is no difference between a high-energy suborbital flight and an orbital flight except for all that horizontal momentum. If you're designing a rocket, your first consideration is what payload you want to get where. Rockets scale really, really badly, which is why we divide them up based on whether they're intended to be used short range, long range, intercontinental, or orbital. Yes, if you're not too picky, you can use an orbital rocket as a ballistic missile, but you're better off designing your rock

  • Why on Earth anyone would make a rocket out of solid fuel is beyond me. It seems unnecessarily hazardous and I don't understand the benefits. Are they gonna sell it to the Russians for giggles?

    • by dbIII ( 701233 )
      It's all there in the summary that you probably should have read before posting so that you don't waste our time.
      • It would seem that technology enthusiasts who have an interest in information systems don't have a strong desire to read about rockets posted on a website that used to be dedicated to news about information systems.
        • by Anonymous Coward on Wednesday December 21, 2016 @07:03AM (#53528673)

          This is news for nerds. Any "nerd" who doesn't think rocketry is awesome should probably turn in their badge on the way out.

        • It would seem that technology enthusiasts who have an interest in information systems don't have a strong desire to read about rockets posted on a website that used to be dedicated to news about information systems.

          If you look at the top of the page, there are many things that Slashdot is about. Technology is one of them.

          And this is technology, and this is of direct interest to many of us - myself included.

          I mean it isn't the level of interest of Vim vs emacs arguments always bring us, or the ever enjoyable password arguments, but some of us have a passing interest in rocketry.

      • It's all there in the summary that you probably should have read before posting so that you don't waste our time.

        Thank you for noticing me, supreme arbiter of the Internet.

        You should probably change the word 'our' to 'my' since have it on good authority that other people actually enjoy laughter.
        On a related note, does it bother you that the Funny mod is +1 and not -1?

        • by dbIII ( 701233 )
          Your thanks is appreciated supreme arbiter of rocketry.
        • by dbIII ( 701233 )

          other people actually enjoy laughter.

          Indeed, but normally it take a little more than acting like a complete idiot to make them laugh instead of just writing you off as a complete idiot.

          • Indeed, but normally it take a little more than acting like a complete idiot to make them laugh instead of just writing you off as a complete idiot.

            Bob, we've already established that you are more of a Krampus than any authority on humour, so this just comes off as sad.

            Are you grumpy because people around you are happy during the holidays?

            • by dbIII ( 701233 )
              I clearly had no way at all to be able to tell the difference between you acting like a total idiot in a failed attempt to be funny or merely being one of the many "it's not US space so let's dump on it without having a clue" losers.
              Please keep that in mind the next time you attempt to be funny but fail so dismally.

              Also why are you trying so hard to convince me you were joking?
              • I clearly had no way at all to be able to tell the difference between you acting like a total idiot in a failed attempt to be funny or merely being one of the many "it's not US space so let's dump on it without having a clue" losers.
                Please keep that in mind the next time you attempt to be funny but fail so dismally.

                This is something you should take up with your grade school teacher and/or parents. I claim no responsibility for your Trump-grade intellect.

                Also why are you trying so hard to convince me you were joking?

                Because your saltiness amuses me.

            • by dbIII ( 701233 )
              Grumpy? From the guy making an attack on JAXA or pretending to do so?
              Now you are making me laugh - what a loser!
              • Bob, you aren't making yourself look better here. It's bad enough to be Krampus, don't be illiterate too. Nobody wants to hug a kid that special.

                Also, you don't have to answer twice to my posts. I get that you need to rest between these intellectual exertions, but it's possible to just save the first response to a text file and then load it up when you have rested.

                You're welcome.

                • by dbIII ( 701233 )
                  You are still trying?
                  Where the fuck was the joke? It looks to me that you just didn't read the summary and wanted to have a go at a rocket scientist to inflate your ego?
                  • Admittedly, you are far better than any joke I could tell, so in that regard you have me beat. Well done.
                    I think we've already covered your personal war on literacy, no need to rehash.

                    • by dbIII ( 701233 )
                      So slang guy is referring to literacy? It appears you only have one card to play even when it is ridiculously inappropriate.
                    • Slang and literacy go quite well together - in both directions one should understand one to fully appreciate the other. Only a special kind of child would fail to make that connection...

                      Other than that, It's not surprising that the boy who hates laughter would find stuff to be "ridiculously inappropriate".

                      Your are just adorable.

                • by dbIII ( 701233 )

                  Also, you don't have to answer twice to my posts.

                  Why not - you replied twice to my initial post after all.
                  Just admit to yourself that you fucked up by not reading the summary before writing your petty attack on JAXA and then later pretended it was a joke to avoid looking like the idiot you are. No need to admit it to me since I worked that out from the start.

                  • Or you could figure out that very few people are so insecure that they would need to lie on a pseudonymous forum. Your projections onto me serve only to embarass and, were this not a pseudonymous forum, humiliate you.

                    • by dbIII ( 701233 )
                      Not as such. Your bluff didn't work loser.
                    • by dbIII ( 701233 )

                      Or you could figure out that very few people are so insecure that they would need to lie on a pseudonymous forum

                      It didn't look like a lie, it looked like full on jingoistic stupidity and despite your backpedalling I think that is what it was since there is not the most remote trace of humour in that first post. The lie comes later with your backtracking and your pointless attacks on me just because I politely pointed out your stupidity.
                      How the hell do you cope if this is all it takes to set you off with th

                    • Haha, you're doing it again. When you grow up you'll understand.

                    • Bob, calm your tits.

                      I don't want you to get a heart attack. You are my Slashdot entertainment for the time being and I want you hale and flailing.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      Much of the cost of a liquid fuel rocket is an engine, here you just have a simple pipe open on one end.

      • by Hognoxious ( 631665 ) on Wednesday December 21, 2016 @07:33AM (#53528719) Homepage Journal

        Usually you have to fill liquid fuelled ones up just before you launch them. This means if anyone is observing you, they know in advance that you're going to launch.

        This can be a disadvantage for certain applic@.m,mk
        no carrier

        • Only cryogenic fuel rockets. Hypergolic fuel rockets can be fuelled way earlier - the missiles can stay fuelled up to a decade or so.

          • "Hypergolic fuel rockets can be fuelled way earlier"

            Those tend to be something you don't want to spend any time in close proximity with. Hypergolic fuels and biologicals tend not to make a good combination - and unlike space, metals tend to corrode when in an atmosphere so the risk of long-term leakage is substantial.

            • When it comes to liquid fuelled ballistic missiles, they usually are factory fuelled (UDMH + RFNA) and are stored that way for "fucking years, absolutely years" and don't leak (that's why they were so expensive to build). And when the ballistic missiles approach the end of their warranty, they can be used for satellite launches.

        • Usually you have to fill liquid fuelled ones up just before you launch them. This means if anyone is observing you, they know in advance that you're going to launch.

          This can be a disadvantage for certain applic@.m,mk
          no carrier

          Yes, but I think they will know you are launching when you go stand this thing up on the launch pad and fuel the second and third stages.

      • It is, but the fuel on the other hand is very cheap, whereas solid propellants can be much more expensive to process, especially for very big rockets. Anyway, building SRBs is more or less a side effect of having missile-equipped military. You don't look at costs at that point.
        • It is, but the fuel on the other hand is very cheap, whereas solid propellants can be much more expensive to process, especially for very big rockets. Anyway, building SRBs is more or less a side effect of having missile-equipped military. You don't look at costs at that point.

          There is some pretty solid science and technical reasons why a strap-on SRB is a more cost efficient way to go than designing and running a liquid fueled rocket capable of running the whole mission.

          Especially that first few thousand feet.

          Do you have any references to solid fuel boosters being more expensive to process than the compression and storage and pumping and evacuation if needed of the liquid fuels? I assume that you are speaking only of hydrogen/oxygen fuel, not the hypergolics or highly refin

          • The sane high-thrust booster choice is RP-1/oxygen or even CH4/oxygen these days. Indeed I'm speaking about the fuel cost. Liquefying oxygen or methane per unit of mass is pretty much the lowest-cost thing one could come up with - below one dollar per kilogram for sure. Mixing a heterogeneous mixture of solids and curing it in a casing is definitely more expensive. Apparently, the cost is something like 50 Euros per kilogram for Ariane 5 boosters. [google.com] Now that's of course meaningless if the liquid rocketry gadg
            • "Apparently, the cost is something like 50 Euros per kilogram for Ariane 5 boosters. "

              The higher cost of the materials is more than offset by not needing to have pesky expensive things like turborocket engines at the blunt end.

              As for the ESA published cost, having worked on the peripherals of the organisation for the last 15 years I could easily believe that figure being 20 times higher than the ACTUAL cost of the material and manufacturing, based on inflation of figures as they pass through the organisatio

              • The higher cost of the materials is more than offset by not needing to have pesky expensive things like turborocket engines at the blunt end.

                The single most important reason for those "pesky expensive things" to still be peskily expensive in the 2010s is that nobody cared about making them cheaper, both in terms of manufacturing and in terms of being able to use them multiple times. Now that companies like SpaceX and BO started caring about these things, there's very likely a shitstorm coming for the legacy designs.

                • You're quite right, but the engines are still expensive enough that virtually all the new designs are centred around getting them back for re-use.

                  If they're basic and cheap enough you can treat them as disposable, but noone is brave enough to make a Sea Dragon (which is reusable anyway).

    • Advantages: (Score:2, Insightful)

      by Anonymous Coward

      Solid fuel: Low cost, low storage requirements, quick preparation

      Disadvatanges:
      Low power, can't be stopped

    • by hey! ( 33014 ) on Wednesday December 21, 2016 @09:24AM (#53528959) Homepage Journal

      US ICBMs are solid fuel rockets. This is so they can be launched quickly before an attack by an adversary can take them out.

      That said the primary design goal for this particular rocket is low cost. One of these particular rockets costs only $38 million. Many launch systems aimed at putting about 1000 kg into orbit are solid fuel because it's relatively cheap to build and operate a solid-propellant rocket and you don't need to squeeze every last bit of specific impulse out of the rocket to launch a modest payload.
      .

    • Why on Earth anyone would make a rocket out of solid fuel is beyond me. It seems unnecessarily hazardous and I don't understand the benefits. Are they gonna sell it to the Russians for giggles?

      Solid fuel is more stable.

      You don't have to fuel right before launch, lose a lot of the fuel and Oxidizer during the runup to launch, and then have to pump it back out if the launch is scrubbed.

      It's really handy for first stage boosters. If you want a lot of boost, a rocket like the Saturn V has to have incredible amount of thrust just to get off the ground. Strap on a couple solid boosters and suddenly you can save the liquid fuel for later in the flight when the throttleability that solid fuel lacks is

    • by gman003 ( 1693318 ) on Wednesday December 21, 2016 @11:46AM (#53529921)

      Solid rocket motors have tradeoffs. In some circumstances, they make sense.

      They are long-term storage-stable. Build it, stick it in a silo somewhere, and leave it be for a few years, it will still launch just fine. Hypergolic liquid-fueled rockets can't be kept ready-to-launch for more than a few days*, and cryogenic liquid-fueled rockets can't be kept ready-to-launch for more than a few hours. This makes them particularly preferable for military uses, everything from little anti-tank rockets to ICBMs. This also reduces the number of ground crew needed - you don't need to worry about fueling, just electricals and signals.

      They have extremely high levels of thrust, due to the extremely high energy density. The Shuttle's SRBs were each twice as powerful as the largest liquid-fueled rockets. This makes them very popular as boosters.

      They have a lot of impulse per unit volume. What most rockets care about is impulse per unit mass (aka specific impulse), but some cases care about volume. If you're launching from an aircraft, like Stratolaunch or Pegasus, this matters. If you have constrained volume because you're in a fixed-size fairing, this matters. If you're launching from a submarine, this matters.

      It's also often a matter of economies of scale. Countries with military missile programs (which have many reasons to go solid-fueled) often use them for other things as well, either to subsidize their military-industrial complex or to take advantage of existing scale to make civilian rocketry cheaper, depending on how cynical you are. The US, masters of solid-fueled ICBMs, used a pair of massive SRBs on the Space Shuttle, and will use them again on SLS, if that ever flies. The ESA's Ariane 5 uses SRBs based on a French SLBM. Japan may not field ICBMs, but they too have a reason - the first stage of this rocket is almost identical to the booster of their H-II rocket.

      The higher stages are solid-fueled presumably to maintain that low-ground-crew capability, and the minor reduction in drag can't hurt either.

    • Cheaper, they have less parts and don't have all of the headaches associated with handling cryogenic fluids. Only their 4th stage uses liquid propellant, hydrazine a monopropellant. Having a 3 stage solid propellent stack is actually quite an achievement.

    • Solid fuel rockets are generally less dangerous than liquid-fuelled ones (until you light them).

      As first stage boosters they're quite useful lifters but I wouldn't want to go to orbit on one.

  • When you launch it, it will shit bricks
  • While solid fuel is not normally considered a good propellant for commercial launch operations, it is very good in case you ever have to field your own ICBM's. With The Donald talking about shaking things up with our allies (saying Japan and South Korea should have their own nukes), this is good expertise to have experience with.
  • From my limited KSP playing experience, the biggest drawback for solid fuel propulsion is the inability to throttle back (or shut down) the rocket.
    I have seen a growing number of non-booster stages that use solid rocket fuel systems. Has this problem been solved?

    • From my limited KSP playing experience, the biggest drawback for solid fuel propulsion is the inability to throttle back (or shut down) the rocket.
      I have seen a growing number of non-booster stages that use solid rocket fuel systems. Has this problem been solved?

      Well, yes and no. A solid-fuel rocket cannot be throttled. But a hybrid system (solid fuel plus liquid oxidizer) can be throttled and/or shutdown, by throttling the flow of oxidizer.

      It's got some of the advantages of solid fuel, and some of the

      • "A solid-fuel rocket cannot be throttled"

        Your hybrid is one approach. The other is to use solids for the lower kick stages and throttleables for the finer work.

        Pegasus being an example of a 3-stager made of solids with a throttleable 4th stage used if needed.

  • ... That Japan has stopped assembling checklists of things to do to build a rocket (then firing them off and finding that things seldom go to plan) and actually started testing every step of the way as well as taking input from the rank-and-file workers (This was one of the prime causes of past failures. Lowly workers would notify that XYZ was incorrect but be overruled by managers who knew better because they were highly paid managers, not lowly workers who actually put the things together(*))

    (*) This cult

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